Chipping hammer



March 16, 1954 H. R. FISCHER 2,672,129 CHIPPINGHAMMER Filed March 17, 1949 5 Sheets-Sheet l H. R. FISCHER CHIPPING HAMMER 7 March 16, 1954 5 Sheets-Sheet 2 Filed March 17, 1949 INVENTOR HIKE 2'2? March 16, 1954 H. R. FISCHER CHIPPING HAMMER 5 Sheets-Sheet 5 Filed March 17, 1949 March 16, 1954 H. R. FISCHER CHIPPING HAMMER Filed March 17, 1949 5 Sheets-Sheet 5 Patented Mar. 16, 1954 CHIPPING HAMMER Howard R. Fischer, Detroit, Mich., assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application March 17, 1949, Serial No. 81,935

4 Claims.

This invention relates to a chipping hammer.

It is an object of the present invention to provide a chipping hammer which is equipped with a high velocity jet blowing device for cleaning the work surfaces which have been worked upon with the hammer that will direct a steady high velocity stream of air from the hammer nose and will remove an accumulation of cuttings that are not removed by the exhaust air of the hammer and wherein the action of the hammer and of the blower is efiected with a common control lever which is squeezed or pushed with the thumb to efiect hammer action and which with the same thumb may be lifted to start blower action and without having to move the hammer to direct the jet of air onto the work surface.

It is another object of the invention to provide a chipping hammer which has a sensitive throttle control whereby the hammer may be easily regulated to deliver either light, delicate taps, or heavy, hammer-like blows and whereby to render the hammer adapted for use for many different purposes.

It is another object of the invention to provide an automatic distributing valve arrangement for delivering air under pressure alternately to opposite sides of the hammering piston comprising separable valve case sections and a valve element having two thin flanges spaced apart and an integral stem guided by the valve case sections and wherein the flanges need not have air tight connection with the walls of the case sections, but between their peripheries and the walls provide the passages through which the air is diverted to the opposite sides of the valve to efiect the movement of the valve from one position to the other and to pass the air to the opposite sides of the hammering piston, whereby to provide a valve arrangement for chipping hammers which will have little wear and long life.

It is another object of the invention to provide a. simple chisel retaining device for chipping hammers which permits the easy removal of the chisel and makes the changing of chisels a simple, easy operation, and whereby when the chisels are in place they are positively retained against outward movement from the hammer casing.

It is another object of the invention to provide a chipping hammer comprising a cylinder sleeve, hammering piston and distributing valve parts which can be loosely assembled in order in the outer casing and which will be held in place by the single connection of a throttle and blower valve containing cylinder head to the outer casing.

Other objects of the invention are to provide a chipping hammer having a jet blowing device, a distributing valve arrangement and a positive retaining device for the chisel, which is of simple construction, has a minimum number of parts, easy to assemble, inexpensive to manufacture, easy to operate, compact, easily held in the two hands and manipulated, and efficient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which Fig. 1 is a perspective view of the chipping hammer embodying the features of the present invention being used on a wall to chip the mortar from between bricks thereof and with the operating lever depressed for chiseling action.

Fig. 2 is a perspective view of the chipping hammer being used on the wall and with the operating lever elevated with the thumb to project the high velocity jet of air upon the work surface to clean the same.

Fig. 2a is a perspective view of the chipping hammer being used to remove weld flux.

Fig. 3 is a fragmentary side elevational view of the chipping hammer with a portion thereof broken away and shown in section through the region of the air jet blower valve and with the operating lever elevated to depress the same for blower action.

Fig. 4 is a longitudinal sectional view of the chipping hammer with the hammering piston projected toward the nose end of the hammer and as viewed on line 4-4 of Fig. 2.

Fig. 5 is a longitudinal sectional view taken on line 5-5 of Fig. 4.

Fig. 6 is a perspective view of the cylinder sleeve removed from the main casing.

Fig. 7 is a longitudinal sectional view of the chipping hammer with the operating lever depressed ior hammering action and as viewed on line 1-1 of Fig. 1.

Figs. 8 and 9 are respectively enlarged transverse sectional views taken on lines 8-8 and 9-9 of Fig. 7.

Fig. 10 is a collective view of the distributing valve casing sections which are in section and of the valve element which is shown in side elevation.

Fig. 11 is an enlarged fragmentary and sectional view of the hammer taken through the distributing valve arrangement with the hammering piston in its rearward position within the cylinder sleeve and the valve element of the valve arrangement being positioned to extend air to the forward part of the cylinder chamber.

Fig. 12 is a fragmentary sectional view similar to Fig. 11, but with the hammering piston extended forwardly in the cylinder to engage with the end of the chisel and with the valve element positioned to extend air to the rear part of the cylinder sleeve.

Fig. 13 is a perspective view of the hammer looking upon the chisel retaining device in the nose end of the hammer for the securement of the chisel.

Fig. 14 is a fragmentary sectional view of the nose end of the hammer taken on line i' -i tdf Fig. 13.

Fig. 15 is a transverse sectional view t'aken on line l5l5 of Fig. 14.

Fig. 16 is a transverse sectional view similar to Fig. 15, but with the retaining plug having been turned to expand the retaining spring and to free the plug of the chisel element for the release of the same.

Fig. 17 is a longitudinal sectional view taken on;line-'l'i-l of Fig. 16. I

Referring now to the figures, the chipping hammer of the present invention comprises generally an outer casing having an integral nose end portion 22 adapted to receive a chisel 23 within its opening 2 lhis chisel 23 is held within the opening 2d-by a quick release key plug 25. lhe outer casing-2i isinternally threaded at 26 to receive a threaded'portion 2'? of a cylinder head 28 having a throttle valve element 253 adapted to be depressed by a manually-operable lever 31 pivotally connected to the cylinder head 28 at 32. This same lever 32 when pivoted away from the throttle valve element 25 is used to depress a blower valve element 33 to cause air to be directed through thecylinder head and casing and holes 34 in the nose end portion 22 of the outer casing 2i todirect air upon the 'worksurface. This air passes to "the work surface with great force and removes such particles andchips from the surface which'havenotbeen removed by the exhaust air blast-and in the'manner as'illustrated in Fig. 2.

Fitted within'the'outer'casing 2i isa'cylinder sleeve 35 having a hammer piston 38 slidable therein. This hainmerxpist'on 3E; hasaprojection 3'iadapted to tap the end orthe chisel '23 which has been extended into the nose end portion of theouter casing 21. Fixed within the outer casingii by'the'cylinde'r head '28 is a distributing valve *arrangement dt with a'double flange valve element 35: and adapted to cause the passage of air to first one end of thecylinder sleeve '35 and then to the opposite end thereof whereby to-cause the reciprocation of the hammer piston 3% ate speed dependent upon the extent of downward movementof the lever'fii and of the throttle valve element 29. The hammer piston 35 can accordingly be made to deliver either fast blows upon the chisel 23 or slow taps.

The cylinder head 28 is locked in the outer casing 2 i, against'turning movement by a locking ring 4! seated in aligned recesses 42 and' lB'of the respectivecasing'and he'ad'p'arts, and having a radially inwardly bent end '45 within aligned peripheral'slots' l5 and as of the respective-casing and head parts. An air hose $8 is ccnnected'to a threaded opening 59 in the cylinder head 23. Extending from this threaded opening td 'is a valve chamber 59 into which valve elements and 33 are extendedto open ports 52 and-53 re spectively. A plug 54 is disposed in a threaded opening at the bottom of the cylinder'head'whereby, if desired, an attachment of the hose 48 can be made to the bottom of the cylinder head. The plug 54 can be then inserted in the threaded opening d9.

Air passes from the valve chamber 5! through port 52 when lever 35 is depressed and the valve element 29 lowered into the chamber 5! so that itsclosing :portion 55 drops sufficiently to allow air to passto a groove 56o'n' the valve element 29 and to distributing valve chamber 5'! in the cylinder head. The valve element 2% is urged toward its elevated and closed position by a spring 58 and plug 59.

The distributing valve arrangement 38 comprises t-WO opposing valve seat parts or casing sections 15! and 52 separable from one another upon the distributing valve arrangement being maaerreetrthe'ca'sing but held closed upon one another by the cylinder head 28 on being connected with the outer casing 2|, Figs. 4, 11 and 12. Circumferentially spaced within the casing section 51 area plurality of longitudinally-extending holes 63 through which the live air is passedp'from the valve chamber '5'! to a manifold recess t lcutin the face of the casing section 61. From the manifold-recess, the live air passes radially inwardly through a thin slot 55 provided between the casing=sections El and 62 and'into space -86 provided between flanges 61 and '68 of valve element-39. This space=55 provides a'miniature reservoir for the air and permits the valve element-'59 to'shiftfrom one positionto-the'other. On the valvecasing section 51 is a seat -59 against which the valve element is forced when moved into casing-section 5!. On thecasing-s'ection 62 is a valve seat lil'against which the valve element 39 is forced whenthe valve element is moved-toward 'thatsection. The valve element --39 base. stem H which enters a hole '12 to be supported and guided in-itsaxial'iiiovement within the'distributing valve casing sections.

The two fianges fi'l' and-fiii of the valve element 39 are slightly smaller in diameter than thebores of the valve-casingsections which allo'w'the'correct volume'of air to flow-past the flanges to the front andiearof the cylinder sleeve-35 to'operate the hammering piston 56. If the valve element =39 has been moved-to the right,"as*viewed in 'Figssb, 7 and 'l'lyair passes fiaiige B'L'seat 69, longitudinally-extending chamber 15 in'th'e valve section 61 radially-extending passage 'lfi aligned peripheralslots 18 and 19 in the respective valve casing sections 6"! and 8-2, longitudinallyextending slot '8l "in the cylinder sleeve 35, holes 82 in the cylinder sleeve 'tothe -front of cylinder sleeve chamber '83 and'ah'eadof the piston 36 whereby to return the pistondfi to *the-iear of the cylinder sleeve chamber. While this 'is taking :place, the air the 'rear of the "chamber -83 isexhausted through large hole 54 th a 'longitudinally extendin'gpassa'g'e dd-Fig.5, provided by relief 86 cut from 'the'exterior of the cylinder sleeve 35. This relief begins-ata point on the cylinder 'sle've removed-'from'the rear end thereof and terminates at the forwar'd end of the cylinder sleeve'to allow the air to pass forwardly thereof to air holes 36 and exhausted upon the working "surface. This air will -'not have the steady and high pressure blowing effector" the "air 'which'is delivered directlywhen the blowing valve-33 is depressed; but will *keep the 'worksurfa'c'e cleared'of the less difficult "cuttings to renidv'e. The manner in which the blowing air arrives or is passd through the partswillbe set-'fofth-date'r herein.

The cylinder sleeve *3 5 has an end" opening 81 through which the hammering portion 37 of the piston 36 is projected. The portion 37 is guided into the opening 87 by a flaring 89. The nose end of the cylinder 35 is peripherally relieved at 89 to provide an annular passage 9| through which the air leaving longitudinal passage 85 passes to air holes 34. The cylinder sleeve 35 has a small bleed port 92 for relieving any pressure back of the piston during the blowing process, otherwise the piston 33 would have a tendency to flutter or make a short stroke.

Forwardly of the hole 84 in the cylinder sleeve 35 is an exhaust hole 93 which is uncovered by the piston as it moves rearwardly in the chamber 83. The pressure in the front end of the chamber 83 thereupon instantly drops. The hammer piston 36 continues to move rearwardly under its momentum and compresses the air in the rear end of the chamber 83 to shift the valve element 39 rearwardly to engage seat 59. The pressure will thereupon drop in the passages leading from the distributing valve 38. The variable force of the blow results from the light sensitive pulley valve element 39, the throttle valve 55 and the control lever 3 I.

The air from the small chamber 66 between the flanges 07 and 63 of the valve element 39 then passes the flange 69, seat 70 and port 94 in the casing section 52, to enter the rear of the chamber 33 to urge the piston forwardly for its next hammering action. As soon as the exhaust port 84 is uncovered on the forward stroke, the pressure on the piston diminishes and pressure is built up between the casing sections to move the valve element forwardly to engage seat 70 and to open the passages to the forward end of the chamber 83 and effect the return of the piston.

While only one relief 35 and one groove 81 has been described, it is to be understood that the cylinder sleeve 35 also has a diametrically opposite relief 06 and a diametrically opposite groove 8|. The valve casing sections BI and 62 likewise have corresponding passages and slots for the delivery of air to the diametrically opposite groove 8|. Likewise, the relief 86 at the opposite side of the sleeve has exhaust openings 04, 92 and 93 and terminates at the annular relief 89 on the nose end of the cylinder sleeve.

Upon release of the operating lever 3|, the

' throttle valve 29 is returned to its closed position and the lever 3| is raised to its neutral position, as viewed in Fig. 4. By lifting the lever rearwardly, the blower valve 33 is depressed and air Will be admitted from the chamber to the blowing air port 53. This blower valve 33 is normally urged toward a closed position by a spring 95 and a plug 95 threaded into the cylinder head 28. There are two ports 53, Fig. 5, connecting respectively with longitudinally-extending passages 97 in the cylinder head 20 which flare outwardly to provide outlet ports 99 on the forward end of the cylinder head.

The cylinder head 28 is provided with an annular recess 99 whereby to provide an annular chamber IIJI between the cylinder head and the casing 2|. This annular chamber I 0| has communication with slots 70 and 79, Fig. 11, in the respective valve casing sections BI and 62 and to the grooves 8| on the exterior of the cylinder sleeve 35. From these grooves, the air enters the front of the chamber 83, causing the hammering piston 36 to be moved rearwardly and to uncover the sleeve opening 93 to permit the air to pass through passages 85, annular space 9| and holes 34. This air moves in a steady stream and will be projected with great force upon the working surface to clear away any accumulation of cuttings for which the exhaust air is not sumcient. It will accordingly be seen, that by simply reversing the movement of the manually-operable lever 3| from its position depressing the throttle valve 29 for chipping action to a position to depress the blower valve 33, blower action will be effected and a removal of the cuttings or' chips on the surface being worked will result.

Referring now particularly to Figs. 13 to 17, there is shown the chisel retaining arrangement. The chisel 23 is generally of square section relieved at its corners, at the portion thereof adapted to fit the opening 24. This portion of the chisel is indicated at I03 and intermediate the length of this portion is a slot I04 adapted to receive the retaining plug 25. This retaining plug is round and has a tapered projection I05 adapted to enter the chisel slot I 04 and a shoulder 95 adapted to engage with a shoulder I07 of plug opening I98 in the nose end 22 of the casing 2|. The retaining plug 25 is held in place with the projection I05 in the slot I04 of the chisel element by a split spring ring I09 adapted to an annular recess I|0 on the exterior of the nose portion 22. The ends of the ring terminate against a handle portion III of the retainer element. On the retainer element below the handle portion is a cam surface I I2 adapted toact upon the ends of the spring ring I09 to expand them and to cause the retainer element to be lifted within the opening I08 and to thereby release the chisel element from its opening 24. The retaining plug 25 is merely turned ninety degrees in order to release the chisel element. Upon the retaining plug being released from spring I99, it will be returned to its lowered position in the chisel slot under the action of the ends of the spring upon the cam surface II2 of the retainer element. The slot I04 in the chisel element is suiiiciently long to permit the axial displacement of the chisel resulting from the hammering action.

The sleeve 35 with the piston 36, the distributing valve sections 0| and 62 with the valve element 39 disposed between them, are easily sembled within the outer casing 2| in the order mentioned and by the mere connection of the cylinder head 28 containing the valves 29 and 33 and the manually-operable lever 3I for operating these valve elements are secured firmly within the casing 2| against axial displacement. The ring 4| is finally snapped into place on the outer casing and the cylinder head to prevent the outward turning of the cylinder head from the outer casing 2|.

The chipping hammer is of light weight, easily handled and has many uses. some of such uses are channeling brick before repainting, cutting windings in electric motors, scraping barnacles from ship bottoms, cleaning putty from stec. window sashes, chiseling wood in pattern shops, making grafting incisions in trees, removing heat treat scale, redressing millstones and numerous other uses.

While various changes may be made in th: detail construction, it shall be understood such changes shall be within the spirit and scope of the present invention as defined by the appended claims.

In a divisional application, Serial No. 367,215, filed July 10, 1953, are claims to the automatic zew m 7 distributing valve arrangement and the chisel retaining iievice, both of which "are diSiiixji-fi herein-an'd ii'lustratedinthe accompanying drawin'g.

What is maimed is:

1. An I air operated chipping "hammer comprisin'g a-cetsing having at one "end a "nose portion including a tool receiving o ening and 'air holes fordirectio'n of air from Said nose portion to a surface being worked upon with the "hammer, a cylinder head remo'vabiy affixed to the other end of the casing and having air inlet meanaa ha-m mer piston arranged for -1'eoip'r0cab1e -movement within the casing, means including passageways for conductingeihaustairfrom the hammer piston 'portion to the air 'ho1es,'-"a throttle Valvea'rranged in the cylinder "head for admission "of live an- "f'o'r aetu'ation of the hammer piston, a blower valve arranged in the cylinder head "for admission of live "air to the passage-aveys leading to the air holes, and a unitary -'control means adapted for operation-of either-the "throttle-valve or theblower valve.

2. "An air operated ohipp'ing hammer accorii ing to c1ai1n*1,-whefein th'e unitary control means compfisesalever which is pivotally arranged so that inone-dhectiomdf movement it operatively engages the throttle valve, and in the "opposite direction of inovement it operativeiy engages the blower "valve.

about the pivot in 3. -An air operated chipping ham'me'r accuramg to claim :2, wherein the length of the lever the direction of the throttle valve is greater than the length of the lever about the pivot in the direction of the blower valve.

'4. *An air opei-at'ed "chipping hammer accor'ding "to claim '3, wherein resilient means are arrangeti io urge both' the throttle "valve and'blower valve toward closed position.

HOWA-RD R. FISCHER.

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